I'm different. I feed rats and on new arrivals I always try a rat first. So far I have never had a new snake refuse. I have also never had to feed live when a snakes previous owner did. I thaw and heat well and have a bit of luck.

If you have more than one snake one trick is to thaw the rats and mice together. This will cross the scents and get the mouse eaters used to the new rat scent.